Typewriter escapement mechanism



o. A. HoKANsoN. TYPEWRITER ESCAPEMENT IVIECHANISM. APPLICATION FILED JULY 24, |918.

2 SHEETS-SHEET I.

I L i Y Patented-June 13, 1922.,

0. A. HOKANSON.

TYPEWHITER ESCAPEMENT MECH/mism.

APPLLCATVION FiLED JULY 24,1918.

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naar aan @T10 A. HQKANSON, 0F WOODSTOCK, ILLINOIS, SSIGNOR T0 WOODSTOCK TYPE- WRITEiB/,COMPANY, F WOODSTOCK, ILLINOIS, A CORPORATION 0F ELLLN'QES.

malades.

Applicationj med July 24,

To all lwhom t may con-cera.'

Be it known that l, O'r'ro A. HoKANsoN, a citizen of the United States, residing at Woodstock, in the county of McHenry and State of Illinois, have invented certain new and' useful improvements ina Typewriter Escapement Mechanism, of which the following is a specification.

rlhis invention relates to typewriters, and more particularly to the escapement mechanism of such machines, and the principal object of the invention is to provide a simple adjustable mechanism of this kind which has a rapid movement and a quick return so that the machine will be both rapid and easily operated. Other objects will appear hereafter.

rl`he invention consists in the novel construction, combination and arrangement of the several'parts. i

ln the accompanying drawings- Fig. 1 is a rear elevation with parts broken away for clearness of an escapement mechanism constructed in accordance with the principles of the invention.

Fig. 2 is a side view of a portion of the mechanism shown in Fig. 1.

Fig. 3 is another side view showing a ditferent portion of the mechanism.

Fig. is a section taken on line 4--eot Fig. 1; and

Fig. 5 is a jiront view of the escapement dogs and the part upon which they are mounted.

@ne of the principal objects of the present invention is to provide means for adjusting the relation between the fixed and movable dogs of the escapement mechanism so that the distance which the carriage of the typewriter moves when the dog ro'cker is rocked rearwardly by the universal bar can be varied, with a corresponding variation ot' the distance that the carriage moves when the rocker is moved forwardly, the sum of the movements being Constant for any given typewriter. lt is also desirable that the movement imparted to the escapement dog rocker maybe as positive as possible, and for the attainment of this end a lost motion connection is provided between the escapement dog rocker and its actuating meanstogether with .suitable stopping means for limiting the movement of the dog rocker.

rli`his invention is applied to a typewriter which has a transversely movable carriage Specification of Letters Eatent.

TYPEWRITER ESCAEEMENT MECHANSM.

Patented June 322,122.

1918. Serial No. 246,460.

impelled by a Suitable motor, usually a spring, (not shown), and carrying an escapement rack l, which meshes with an escapement pinion 2, connected with an escape wheel 3, and suitably mounted in a frame 4. The impelling means :for the escapement mechanism may comprise a horizontally reciprocable universal bar 5, which is actuated by the engagement of type bars that are in turn operated by pivoted key levers (also not shown), and the movement ot" the universal bar 5 in one direction is opposed by means of a spring 6 which is attached at one end to a suitable fixed portion of a 'typewriter frame, and at the other end to a stud 7 carried by the universal bar. rlfhe parts referred to which are not shown are of the usual well-known typewriter construction. and it is not necessary to show them in detail in order to have a proper un' derstanding of the escapement mechanism, whichis the subject of this invention. Depending from the frame 4iare projections 8 and 9 in which a pivot pin 10 is mounted by means of bearing studs 11 in which the pointed ends 120i the pivot pin 10 are mounted. rllhese bearing studs 11 are adjustable in perforations in the projections 8 and 9, and a set screw 18 is provided for holding each or" the studs in its adjusted position. Secured to this pivot pin 10, by means of a set screw 14, is an escapement dog rocker 15 which has an arm 16 extending toward one oi the projections 8. to which is secured at its lower end a channel member 17 with parallel depending sides 18, between which the extremity of the arm extends. Threaded through each of the sides 18 from, the outside thereof is a stop screw 19 with a lock nut 20 disposed thereon for limiting the position of the set screw so that the movement or" the arm 16 in both directions is limited b v the stop screws.

lso pivoted in the projections 8 and 9' b v means of pivoting studs 21, which are held adjustably in position by set screws 22, is a yoke 23 which has depending arms extending around the pivot pin l() and below it. where extremities 25ct the universal bar 5 are pivoted. One of the arms 24 oi this yoke is formed with a forked end 26. portions of which are disposed on each side of the arm 16 adjacent the extremity of the arm. rlhe arm carries an adjustable abutment screw 27 which is slightly less in length than the distance between the forked ends 2 6 of the arm 24, so that there is a little lost motion between this portion of the yoke and the dog rocker arm 16, and a set screw 28 is rovided for holding the abutment screw 27 in any adjusted position.

Mounted on the dog rocker l5 is a fixed dog 29 anda movable dog 30. The fixed dog has a tooth 31 normally out of engagement with the escape wheel 3, and it is formed with a slot 32 curved about the axis of the escape wheel as a center, with attachment screws 33 threaded into the dog rocker 15, so

'that the fixed dog can be moved in an arc limited by the slot 32 always holding the engaging face of the tooth 31 on a radial line with respect to the axis of the escapement wheel 3, so that the straight portion of the tooth 31 will engage the straight portion of the teeth of the escape wheel regardless of the position in which the fixed dog is adjusted by means ofthe slot and the fastening screws 33.

The movable do 30 has an elongated slot 34 by means of w lich it is pivoted upon a fixed pin 35 carried by the dog rocker 15, and below the slot 34 is an arm 36 to which is secured one end of-a spring 37 extending.

through an opening 38 in the dog rocker, and attached at its other end to a support 39 which is fixed to the inside of the dog rocker, as shown more clearly in Fig. 5, by means of fastening screws 40. This support hasa projection 41 extending over the top of the dog rocker for limiting the upward movement of the movable dog 30. This movablel dog 30 has a tooth 42 which is held normally in the path of the escapement wheel teeth, and when the dog rocker 15 is moved to free the movable dog from engagement with the escapement wheel, the spring 37 pulls the movable dog forwardly to the limit of movement allowed by the slot 34, so that the extent of movement of the escape wheel, and consequently of the typewritercarriage itself is lnnited by the length of the slot 34. The spring 37 not only pulls the movable dog horizontally in one direction," but it also tends to rotate the dog upon its pivot 35, holding it upwardly agamst the projection 41. The purpose of this construction is to allow the movable dog to be depressed by the escape wheel when the typewriter carriage is moved in. a' direction reverse to that indicated by the arrow in Fig. 1.

In order to release the escape wheel from engagement with the movable dog and its tooth 42 for tabulating purposes, the mov` able dog is provided with an extension 43, and mounted in a bracket 44 secured to one of the frame parts is a tabulating lever 45 which has a projection 46 overlying the extension 43, and also an arm 47 adapted to be engaged and moved by a roller 48 operated by the tabuiating mechanism, (not shown),

so that the engagement of the arm 47 by the roller 48 will rock the lever 45 to engage the projection 46, with the extension 43 depressing this end of the loose dog until the tooth 42 is free from engagement with the escape wheel, whereupon the typewriter carriage and the rack 1 are free to move in the direc tion of the arrow in Fig. 1 under the impulse of -the carriage motor, in the well-known manner. The lever 45 is normally pressed out of such engagement by means of a spring 49, and the tooth 42 of the movable dog is, of course, returned to its engaging position by means of its spring 37.

One side of the tooth 31 of the fixed dog is preferably formed with a beveled surface 50, as shown more clearly in Fig. 5, which engages the escape wheel, as shown, in Fig. 3, when the dog rocker is rotated upon its pivot, and the tendency of this beveled surface is to return the dog rocker to its normal position or out of engagement with ,the escape wheel, thus resulting in a quick action or quick return of the escapement.

A bent rod 51 is also attached to one of the frame projections 8 by means of a set screw 52. and one end of a coil spring 53 is attached to the rod, the other end of the spring being attached to a perforated projection 54 of the dog rocker for returning it to normal position with the movable dog in engagement with the escape wheel. If desired, the yoke 23 may be provided with a rearward projection in which an adjustable stop screw 55 is threaded having a lock nut 56 for holding it in any adjusted position to cooperate with an adjustable screw 57 which is threaded in the adjacent frame 4. This construction, however, is not absolutely necessary if both set screws 19 are provided for limiting the movement of the dog rocker arm 16.

In operation, the fixed dog 29 is first set or adjusted by means of the slot32 and the screws 33, so that'the tooth 31 is at the desired distance from the normal position of the tooth 42, as shown in F'ig. 1, to allow a predetermined movement of the escape wheel, and consequently of the carriage, when the dog rocker is first moved in one direction. The adjustment of this fixed tooth is determined in practice principally by the question of whether a speedy orrelative slower action of the escapement mechanism is desired, fast operators requiring a more speedy act-ion than slower operators. Assuming that this adjustment and the other adjustments of the set screws 19 and 27 have been made, the dog lrocker is normally in the position shown by Fig. 1 with the tooth of the movable do in engagement with the escape wheel and wlth the universal bar 5 in its forward position holding Athe rear fork 26 of the yoke 23 against the head of the abutment screw 27. In this position the arms 16 of the dog rocker 15 are held in engagement with the forward set screw 19 by the spring 53. When theuniversal bar 5 is moved rearwardly against the tension of its returning spring 6, the first portion of the movement takes up the lost motion between the front fork 26 (see Fig. of the yoke arm 24 and the abutment screw 27, which insures that there must be a positive movement of the universal bar, and consequently of its actuating means before any movement .is imparted to the escapement dog rocker. The continued movement of the universal bar 5 causes the rearward movement of the dog rocker arm 16 until the loose dog is disengaged and the fixed dog is engaged, as shown in Fig. 3, and in this position the escapement wheel has moved the distance between the normal position of the .movable tooth 42 and the set position of the fixed tooth 31, as shown in Fig. 1 This movement of the dog rocker is limited by means of the other set screw 19 which engages the arm 16, and it may also be limited by the engagement of the set screw 55 carried bythe yoke 23 with the abutment screw 57. 'llhe printing action is usually timed to occur immediately upon the above described movement of' the dog rocker and of the escapement wheel and carriage, immediately after which the printing type bars fall back to their at rest position, whereupon the universal bar 5 is moved forwardly by its sprin 6. The forward movement of the universa bar allows the spring 53 to return the-dog rocker to its normal position with the tooth 42 in engagement with the succeeding tooth of the escapement wheel which concludes the latter space movement of the escape wheel in the well-known manner. It is evident therefore that the mofvement of the do rocker is limited by the set screws 19 and t at the movement of the universal bar is limited and controlled by the engagement of the forks 26 with the abutment screw 27. The adjustability of the fixed dog 29 offers the greatest possible range for varying the speed of the esoapement mechanism, and-.this variation is extremely simple because the adjustment is so accessible.

For convenience in assembling the extensions 8 and 9 might be on a plate separate from. the top plate, and the escapement mechanism shown could be independently assembled, making it a unit asembljg and then secured to the top plate.

1. In an escapement mechanism, an escape wheel having teeth with radial portions, a movable rocker, a movable dog with a tooth to engage the escape wheel teeth, and a dog adjustably fixed to the rocker having a tooth with an abutment surface and means for nlaintaining said surface always radially disposed with respect to the escape wheel.

2. In an escapement mechanism, an escape wheel having teeth with radial abutment portions, and a fixed dog having a tooth also with a radial abutment surface and adjustable on an arc of which the axis of the escape wheel is the center.

3. In an escapement mechanism, an escape wheel, a dog arranged to constitute a fixed stop for said escapement wheel'but oscillatable into engagement with the escapement wheel and adjustable upon an arc and means for automatically holding said dog during said adjustment so that the engaging portion of the dog is always radially disposed with respect to the escape wheel.

1. In an escapement mechanism, an escape wheel having teeth with radial abutting surfaces, and an adjustable dog having a tooth with a corresponding surface and means including a curved slot to adjust the engaging position of the dog tooth but to alitomatically maintain the radial relation thereof to the escape wheel at all positions of adjustment of said dog.

5. In an escapement mechanism. an escape wheel, and an adjustable normally fixed dog carried thereby for engagement with the wheel, and an adjustable normally fixed dog having a curved slot for guiding said dog 6. In an escapement mechanism, a toothed escapement wheel, a rocker pivoted to move transversely to the plane of said wheel, and a dog normally fixed to the rocker but adjustable thereon and having a tooth with an enga ing face extending radially of said whee for all positions of adjustment of said tooth which face is engaged by the teeth of the wheel.

7. In an escapement mechanism, a pivoted escapementdog rocker having an extending arm, and means including a fixed member having depending sides between which the said arm extends and is movableffor limiting 'the' movement of the arm in both directions. 1

8. In an escapement mechanism,a pivoted escapement dog rocker having an extending arm, means including a fixed member having depending sides between which the said arm extends and is movable, and adjustable ,set screws extending inwardly through the sides.

9. In an escapement mechanism, an escape wheel, a dogrocker therefor having an extending arm, means for limiting the movement of the arm 4, in both directions, and means for operating the rocker comprising a pivoted yoke with a forked extremity one portion of which extends on each side of the arm.

10. In an escapement mechanism, an escape wheel, a pivoted dog rocker therefor having an extending arm, means for operating the rocker comprising a reciprocable bar, a pivoted yoke supporting one end of the bar and having an varm with a divided extremity one portion of which extends on each side of the ai'm to engage and move the arm when the said bar is moved, and means for limiting` the movement of the arm in both directions.

11. ln an escapement mechanism,'an escape wheel, a pivoted dog roc-ker therefor having an extendingr arm, a reciprocable universal bar, a pivoted yoke for supporting the rear of the universal bar and having a forked extremity extending on both sides of the arm, and adjustable abutment means in the arm to make a lost motion engagement with the forked extremity.

12. ln an escapement mechanism, an escape wheel, a pivoted dog rocker therefor, means for operating the rocker comprising a universal barand a yoke in which the bar is pivoted having a forked portion extending on both sides 0f the rocker, ineansforming a lost motion connectionbetween the forked extremityv and the rocker, a fixed member having sides which also extend on both sides of the rocker, and adjustable means in the said sides for limiting the movement ofthe rocker in both directions. j

13. ln an escapement mechanism, a toothed escape wheel, a pivoted dog rocker therefor, means for oscillating the rocker, a loose dog having a tooth normally engaging the escape wheeland a slot by which the dog is mounted for pivotal and longitudinal movement, a member attached to the rocker extending over the top of the movable dog for limiting its upward movement, and a spring connected to the movable dog and to said member tending to press the tooth upwardly and the dog iii engagement with the overlying portion of the member.

14. ln an escapement mechanism, an esape wheel, a frame in which the wheel is mounted having` depending portions, a dog rocker for the escape wheel, a pivot upon which the dog rocker is adjustably secured, adjustable means in said depending portions for mounting the said pivot, and operating means for the rocker comprising a yoke and means for adjustably pivoting the yoke in the said frame portions above the pivotal mounting of the dog rocker. g

15. ln an escapement mechanism, an es- -ape wheel, a pivot-ed dog rocker therefor having an extending arm, means forming an adjustable lost motion connection for operating the rocker and for positively moving it in one direction, resilient means for return- .ing the operating means and said lever to normal position, and means for adjustably limiting the movement of the rocker in both directions.

16. In an escapement mechanism, an escape wheel, a pivoted dog rocker therefor having an extending arm, means for operating the rocker comprising a forked member having a lost motion connection with the arm, adjustable stops for limiting the movement of the arm in both directions, and an additional abutment for the forked member comprising an adjustable abutment screw carried thereby and a fixed abutment with which it contacts in one direction of movement thereof.

17. In the carriage escapement of a typewriting machine, the combination with an escapement wheel, of cooperating escapemeiit devices including a rigid dog with provision for adjusting said dog in a circular path about the axis of said wheel, and means for securing said dog in its adjusted positions.

18. ln the carriage escapement of a typewriting machine, the combination with an escapement Wheel, of cooperating escapeinent devices including a dog support, a dog fast on said support and having therein an arcshaped slot with its center of curvature in the axis of said wheel, said slot allowing of an adjustment of said dog in a circular path, and means for securing said dog in its adj usted positions.

19. ln a carriage escapement of a typewriting machine, the combination with a toothed escapement rack, a dog rocker vibrating transversely of saidrack and a normally engaged dog, of a normally disengaged dog, and means for affording an adjustment of said normally disengaged dog on said dog rocker in the direction of motion of the engaged tooth of said rack to vary the extent of drop and for securing said dog in its adjusted positions on said dog rocker, said adjusting and securing means being adapted to determine automatically a line contact between said dog and tooth in the different adjusted positions of said dog.

En testimony whereof l have signed my name to this specification on this 29th day of June, A. D. 1918.

v OTTO A. HOKANSON. 

